As imaging technology advances, the quality of output as well as the quantity of output per unit time continues to increase. In response to these advances, higher quality print substrates have been proposed and utilized, and more reliable and larger capacity sheet feeding mechanisms have been incorporated. Most notably, the speed of printing, especially in duplicating devices, has increased dramatically in recent years. As a consequence of this increase in output speed, higher capacity sheet storage devices have become desirable. Many of these storage devices have been integral with the printing or duplicating units as generally only dedicated, high-speed units have needed such capacity. However, medium to high speed printing and duplicating machines have become increasingly available at prices affordable by small business.
Unfortunately, these devices, while quick and generally reliable, have limited sheet capacity due in large part to the costs (and size) of providing a dedicated, high capacity storage device for light duty units. Thus, a need exists to provide a simple accessory to store large quantities of cut sheets for use in non specialized printing and duplicating. Preferably, such a device would be transportable and interface easily with a variety of printing and duplicating devices.
A constant concern in the image producing industry is sheet feed jamming. The possibility of sheet jams in a printing or duplicating device requires that a person monitor the progress of the print job, identify the location of a jam, clear the jam, and resume the print job. It is therefore important that any high capacity printing or duplicating device utilize a reliable means for transporting a sheet from a stack of sheets to minimize jam potential. Such a means becomes even more important when utilizing a large capacity feeder that is designed to replace an original equipment component. Previous efforts to provide a non-integrated, large capacity sheet feeding accessory have often relied upon sequentially presenting sheets to the feeder mechanism of the printing device and/or sensing the startup and rotation rate of the feeder mechanism to trigger a complimentary response in the sheet transport mechanism associated with the accessory. Such efforts have resulted in complex devices often times having less than desirable reliability.